Analysis and Treatment of Periodic Vibration Alarm of Nuclear Power Turbine Unit

In recent years, many megawatt nuclear power turbine units of China appear rare periodic fluctuating vibration and some units even cause vibration alarm. In order to solve the alarm problem, firstly, the fluctuation period and amplitude of the vibration were analyzed, and then the frequency spectrum was investigated. After analyzing the vibration change and rise, the main reason was the 1 time frequency increase. Afterwards, the reasons for the increase in vibration 1 time frequency were analyzed, and corresponding system operation adjustment and mitigation measures were formulated, and operation adjustments such as hydrogen temperature, oil-hydrogen pressure difference and oil temperature were carried out, which did not effectively solve the problem of vibration alarm under full load. Subsequently, the dynamic balance was arranged at the mediation window. The position and strategy of dynamic balance were analyzed. In the unfavorable situation that dynamic balance did not carry out in the same type machine at the same position, in order to ensure the success of the full load alarm counterweight, the coping strategy of dynamic balance adjustment under no load was formulated. Finally, the problem of vibration alarm under full load was successfully solved at one time, and the vibration reduction was about 40%. The results show that the cause analysis is correct, the measures are effective and the unbalance is reduced, which not only reduces the average vibration level, but also helps to reduce the amplitude of periodic vibration fluctuation.